Cistern syphon sizes.

[Des Jennings]

Whilst sourcing a toilet cistern syphon I've noticed that every outflow pipe dia is 38mm whilst the hole on my cistern to take a new syphon is 50mm dia. There cold be a problem when tightening up the nut onto the rubber washer ie not enough material to tighten up onto. Have I got an unusual cistern or am I worrying too much?

Thanks.

 

[Deleted member 267285]

No, a lot of close coupled outlets are 50mm, some are 60mm. 38mm sounds like an 1” and 1/4 syphon. Lots of push button outlets as said are bigger.

 

[Elkato531]

Replace with a fluidmaster flush valve. Adapts to fit different sized outlets.

 

[Des Jennings]

Replace with a fluidmaster flush valve. Adapts to fit different sized outlets.

Thanks. Will the fluidmaster fit an external lever flush?

 

[Des Jennings]

No, a lot of close coupled outlets are 50mm, some are 60mm. 38mm sounds like an 1” and 1/4 syphon. Lots of push button outlets as said are bigger.

Thanks. The outside dia of the threaded pipe is given as 1.5 inches on the syphon I was looking at.

 

[Deleted member 267285]

Thanks. The outside dia of the threaded pipe is given as 1.5 inches on the syphon I was looking at.

Sorry, my mistake, yes, majority of flush pipe are 1.5”, some of the very older ones were 1.25”.

 

[Deleted member 267285]

Thanks. Will the fluidmaster fit an external lever flush?

Have a look here: https://www.fluidmaster.com/toilet/part-type/flush-valves/

 

[Elkato531]

Will the fluidmaster fit an external lever flush?

Fluidmaster Lever Dual-Flush Valve | Fill & Flush Valves | Screwfix.com